deep veins of lower limb

例句：

1. 1.Deep veins are often the first sign of an infection.
   深静脉通常是感染的早期迹象。
2. 2.The doctor removed a deep vein in my leg to relieve pressure.
   医生从我的腿上移除了一个深静脉以缓解压力。
3. 3.Deep veins can be a source of pain and discomfort during exercise.
   深静脉在运动时可能会引起疼痛和不适。